Certain vehicles, such as, for example, agricultural vehicles (e.g., harvesters, combines, tractors, etc.) and construction vehicles (e.g., bulldozers, front-end loaders, etc.), are used to perform work on ground surfaces that are soft, slippery and/or uneven (e.g., soil, mud, sand, ice, snow, etc.).
Conventionally, such vehicles had have large wheels with tires on them to move the vehicle along the ground surface. Under certain conditions, such tires may have poor traction on some ground surfaces and, as these vehicles are generally heavy, the tires may compact the ground surface in an undesirable way owing to the weight of the vehicle. As an example, when the vehicle is an agricultural vehicle, the tires may compact the soil in such a way as to undesirably inhibit the growth of crops. In order to reduce the aforementioned drawbacks, to increase traction and to distribute the weight of the vehicle over a larger area on the ground surface, track systems were developed to be used in place of at least some of the wheels and tires on the vehicles.
The use of track systems in place of wheels and tires, however, does itself present some inconveniences. One of the drawbacks of conventional track systems is that they tend to decrease the ride comfort experienced by the operator of the vehicle because the air cushion provided by a tire (between each wheel and tire) is not present in such track systems. Thus, vehicles equipped with such track systems in place of wheels and tires are typically subjected to an increased amount of vibration and vertical displacement when driven on uneven surfaces (as compared with the same vehicle having a wheel and tire), because the lack of an air cushion means there is no damping that would otherwise be provided if there were. In addition to potential increased operator discomfort, these vibrations and vertical displacements can potentially lead to premature wear of the vehicle, its component parts, and/or its attached accessories and equipment. Under certain conditions and at certain speeds, vertical displacements and vibrations transferred to the chassis can be so significant that it may be required to slow down the vehicle.
United States Patent Application Publication No. 2015/0266524 A1, published Sep. 24, 2015, and entitled “Crawler Vehicle”, provides what is purported to be an improved track system in view of the vibrations which may occur with track systems described hereinabove. According to its abstract, the '524 US Publication describes a technology wherein: “A crawler vehicle has a body and at least one left and one right track roller unit. The track roller units are connected to the body via a machine axis. The track roller units comprise a first and a second guide roller as well as a first and a second supporting arm on which the guide rollers are mounted. The first and the second supporting arms of each roller unit are mounted to be pivotable independently of one another about the machine axis.”
While the technology described in the '524 US Publication may indeed ameliorate some of the drawbacks of conventional track systems, continued improvement in this area is desirable.